I mean, exactly how invasive are default operating systems? (Like Windows, Mac, Chrome OS, Android, iOS) Do they log your keystrokes, log passwords, capture screen, upload your photos, videos, or audio? (Assuming you aren’t a target of government) Is it even possible for the average person who doesn’t feel comfortable messing with installing operating systems to have any privacy?
One easy way to start is not by doing it all at once. Start by avoiding the Playstore and using fdroid instead. On your main OS replace proprietary software with foss alternatives. Once you get comfortable with that, THEN you can make the next steps. It doesn’t have to happen overnight, but you’ll be heading in the right direction:)